Method and communication system for selecting a transmission mode for transmitting payload data

Abstract

A transmission mode selection for packet-oriented transmission of useful data between a first and a second communication device is provided, where lists of transmission modes for the communication devices are transmitted to a quality-of-service device. The quality-of-service device uses available transmission resources to select one or more transmission modes from the lists such that the quality of service, which is dependent on the selected transmission modes, can be assured by the available transmission resources. The selected transmission modes are transmitted to a connection controller which prompts further selection of a transmission mode from the transmission modes for the communication devices. The useful data are then transmitted between the communication devices using the transmission mode selected by the further selection.

The invention claimed is: 
     
       1. A method for selecting a transmission mode for transmitting payload data between a first communication device and a second communication device over a packet-oriented communication network, wherein a quality-of-service of the transmission is dependent on the respective transmission mode, the method comprising:
 transmitting a first list of transmission modes and a second list of transmission modes to a quality-of-service device that is not either of the first and second communication devices, the first list of transmission modes supported by the first communication device, and the second list of transmission modes supported by the second communication device, the second list generated independently of the first list; 
 selecting at least one transmission mode from the first and second lists by the quality-of-service device based on available transmission resources of the communication network such that the quality of service dependent on the selected at least one transmission mode is guaranteed by the available transmission resources; 
 transmitting the selected at least one transmission mode from the quality-of-service device to a data link control, the data link control not being one of the first and second communication devices, not being a component of either of the first and second communication devices, not being a component of the quality-of-service device, and not being the quality-of-service device; 
 initiating a further selection of a transmission mode by the data link control, the further selection based on the selected at least one transmission mode transmitted to the data link control; and 
 transmitting the payload data between the first and second communication devices using the transmission mode selected in the further selection. 
 
     
     
       2. The method as claimed in  claim 1 , wherein the at least one transmission mode selected by the quality-of-service device is supported by both the first and second communication devices, and wherein the further selection initiated by the data link control comprises the data link control performing the further selection of the transmission mode by:
 communicating the further selection of the transmission mode by the data link control to the first and second communication devices such that the transmitting of the payload data between the first and second communication devices using the transmission mode selected in the further selection is performed without the data link control querying the first and second communication devices to make the further selection. 
 
     
     
       3. The method as claimed in  claim 1 , wherein a preselection is made for the first and second lists to be transmitted such that the first and second lists include only transmission modes that are supported by both the first and second communication devices and that the first and second lists are created from the preselected transmission modes. 
     
     
       4. The method as claimed in  claim 1 , wherein to create at least one of the lists, the transmission modes are determined from at least once condition selected from the group consisting of a connection setup signaling for the transmission of the payload data, a preceding signaling, a registration of the communication device of the list with the data link control, and a configuration of the data link control. 
     
     
       5. The method as claimed in  claim 1 , wherein when a plurality of transmission modes are selected by the quality-of-service device, each selected mode is assigned a different priority level to provide a recommendation for the further selection. 
     
     
       6. The method as claimed in  claim 1 , wherein a transmission mode specific comparison of a required bandwidth with an available bandwidth is performed during the selection of the at least one transmission mode by the quality-of-service device, and a bandwidth reservation is made based on the selection. 
     
     
       7. The method as claimed in  claim 6 , wherein the comparison of a required bandwidth with an available bandwidth is performed as part of a call acceptance check. 
     
     
       8. The method as claimed in  claim 1 , further comprising:
 the data link control transmitting the further selected transmission mode to the quality-of-service device prior to a start of the transmitting of the payload data between the first and second communication devices using the transmission mode selected in the further selection, and 
 requesting, by the quality-of-service device, a bandwidth reservation in accordance with the further selected transmission mode. 
 
     
     
       9. The method as claimed in  claim 1 , further comprising:
 the data link control transmitting the further selected transmission mode to the quality-of-service device; and 
 updating, by the quality-of-service device, a previous bandwidth reservation in accordance with the further selected transmission mode. 
 
     
     
       10. The method as claimed in  claim 1 , wherein the first communication device transmits the first list of transmission modes to the data link control via a signaling message intended for the second communication device, wherein the data link control delays forwarding of the signaling message and transmits the first and second lists to the quality-of-service device, and wherein the initiating of the further selection of the transmission mode by the data link control comprises:
 modifying, by the data link control, the delayed signaling message after the data link control receives the at least one transmission mode selected by the quality-of-service device such that the transmission modes of the signaling message are replaced by at least a portion of the at least one transmission mode selected by the quality-of-service device, and 
 transmitting, by the data link control, the modified signaling message to the second communication device. 
 
     
     
       11. The method of  claim 1 , wherein the data link control is a network node, a gateway or a gatekeeper. 
     
     
       12. The method of  claim 1 , comprising:
 transmitting the first list of transmission modes to the data link control by the first communication device; 
 transmitting the second list of transmission modes to the data link control by the second communication device prior to the first list of transmission modes being transmitted to the data link control by the first communication device; and 
 wherein the data link control transmits the first and second lists of the transmission modes to the quality-of-service device. 
 
     
     
       13. The method of  claim 12 , wherein the first and second lists are modified by the data link control and merged into a single list for transmission of the first and second lists to the quality-of-service device. 
     
     
       14. The method of  claim 12 , wherein the data link control initiates the further selection of the transmission mode after receipt of the selected at least one transmission mode transmitted by the quality-of-service device, the initiation of the further selection of the transmission mode comprising:
 transmitting, by the data link control, a first message to the second communication device identifying the at least one transmission mode selected by the quality-of-service device; 
 transmitting, by the data link control, a second message to the first communication device identifying the at least one transmission mode selected by the quality-of-service device; 
 transmitting, by the second communication device, a selection of a single transmission mode of the at least one transmission modes selected by the quality-of-service device in response to the first message from the data link control; and 
 transmitting, by the first communication device, a selection of a single transmission mode of the at least one transmission modes selected by the quality-of-service device in response to the second message from the data link control. 
 
     
     
       15. The method of  claim 14 , wherein the first list identifies codecs supported by the first communication device and the second list identifies codecs supported by the second communication device. 
     
     
       16. A communication system for selecting a transmission mode for transmitting payload data between a first communication device and a second communication device over a packet-oriented communication network, wherein a quality of service of the transmission of payload data is dependent on the transmission mode to be used for transmitting the payload data, the system comprising:
 a quality-of-service device for: receiving a first list of transmission modes supported by the first communication device, receiving a second list of transmission modes supported by the second communication device, the second list generated independently of the first list, selecting one or more transmission modes from the first and second lists on the basis of available transmission resources of the communication network such that the quality of service dependent on the selected one or more transmission modes is guaranteed by available transmission resources, and transmitting the selected one or more transmission modes to a data link control, the quality-of-service device not being either of the first and second communication devices and not being a component of either of the first and second communication devices; and 
 the data link control for initiating a further selection of a transmission mode from the one or more transmission modes for the first and second communication devices selected by and transmitted by the quality-of-service device, the data link control not being one of the first and second communication devices, not being a component of either of the first and second communication devices, not being a component of the quality-of-service device, and not being the quality-of-service device; and 
 a transmission device for transmitting the payload data between the first and second communication devices using the transmission mode selected via the further selection. 
 
     
     
       17. The system of  claim 16 , wherein the data link control is a network node, a gateway or a gatekeeper. 
     
     
       18. The system of  claim 16 , wherein the at least one transmission mode selected by the quality-of-service device is supported by both the first and second communication devices, and wherein the further selection initiated by the data link control comprises the data link control performing the further selection of the transmission mode by communicating the further selection of the transmission mode by the data link control to the first and second communication devices such that the transmitting of the payload data between the first and second communication devices using the transmission mode selected in the further selection is performed without the data link control querying the first and second communication devices to make the further selection. 
     
     
       19. The system of  claim 16 , wherein the data link control is configured to transmit the further selected transmission mode to the quality-of-service device prior to a start of the transmitting of the payload data between the first and second communication devices using the transmission mode selected in the further selection, and
 the quality-of-service device is configured to request a bandwidth reservation in accordance with the further selected transmission mode.